U.S.-listed ETFs had $570 billion in assets as of Jan. 31, down $37.5 billion or 6.2% from the previous month. A report by SSgA blamed the decline on weak domestic and international equity markets. There were 634 ETFs in January, including five new funds. BGI remained the largest ETF provider, with 53.8% of total market share. SSgA was second with 25.7% and Vanguard was third with 7.3%.